Former Microsoft CEO Steve Ballmer on Friday filed a motion to dismiss a lawsuit brought against him by a retired Seattle scientist who claims the billionaire promised to pay a debt on a friend’s behalf.

Thomas Bukowski last month added Ballmer to a lawsuit he had filed against former Sonics employee Steve Gordon.

The suit claimed that Gordon, known as the “Hat Man,’’ owes Bukowski $3 million on a business deal and that Ballmer had pledged in an email last summer to pay it back, along with a group of other debts.

But Ballmer severed ties with Gordon last July after initially helping him repay one $50,000 debt.

The motion to dismiss the lawsuit states that Bukow­ski’s complaint “alleges nothing more than a promise by Ballmer to consider providing financial assistance to Gordon’’ and is not a claimed agreement to follow through.

According to the motion, Ballmer told Gordon he would have to seek treatment for depression at a Texas psychiatric hospital called the Menninger Clinic before he’d consider helping him.

Ballmer flew Gordon there last June on his private jet and paid for a six-week stay.

Earlier this month, Ballmer made headlines with a $2 billion purchase of the Los Angeles Clippers from embattled owner Donald Sterling.

Geoff Baker: 206-464-8286

or gbaker@seattletimes.com